1Department of Entomology and Agricultural Zoology, Tirhut College of Agriculture, Rajendra Agricultural University, Dholi, Muzaffarpur-843 121, Bihar (India).
2Department of Entomology, Haryana Agricultural University, Hisar-125 004, Haryana, (India).
Combined effects of constant temperature (15–35°C) and relative humidity (50–90%) on the longevity, fertility and total developmental duration of Ooencyrtus papilionis Ashmead, an egg parasitoid of the sugarcane leaf hopper, Pyrilla perpusilla Walker, were determined. Influence of the temperature on different biological parameters, viz., longevity of male and female, fertility-fecundity (eggs/female), duration of life cycle and emergence, was highly significant. The relative humidity, on the other hand, did not produce any marked change. Average longevity of males decreased from 6.49 to 1.55 days and that of females from 9.65 to 1.62 days in response to corresponding rise in test temperature from 15 to 35 ± 1.5°C. Both at 15 and 35°C, the parasitoid female ceased to lay eggs and its fecundity went on increasing with the rise in temperature from 17.5 to 27.5 ± 1.5°C but gradually declined with further rise in temperature. Mean duration of its life cycle declined from 45.81 to 9.97 days as the rearing temperature was raised from 15 to 32 ± 1.5°C. Developing parasitoid died, without attaining adulthood within its host eggs, at or above 35°C. The adult emergence was the maximum (96.9%) at 27.5 ± 1.5°C, whereas the average percentage of females declined from 69.3 at 17.5 ± 1.5°C to 52.4 at 32.5 ± 1.5°C.
